Life imitates art in visualizing Internet addresses

October 13th, 2007

Map of the Internet The ANT Censuses of the Internet Address Space project at ISI has been collecting data by actively pinging all addresses in the allocated Internet address space. Amazingly, the visualization technique they used was inspired by one used for the same purpose in an xkcd webcomic.

“The figure above shows our map of the allocated address space. They layout follows Randall Munroe’s hand-drawn map of allocated Internet address blocks from xkcd #195. We convert the one-dimensional, 32-bit addresses into two dimensions using a ilbert Curve, as shown to the right. This curve keeps adjacent addresses physically near each other, and it is fractal, so we can zoom in or out to control detail.”

New W3C Semantic Web Logo

October 12th, 2007

I like the new W3C Semantic Web logo. It’s more stylish than the old RDF logo and has a better explanation:

“The three sides of the tri-color cube in these logos evoke the triplet of the RDF model. The peeled back lid invites you to Open Your Data to the Semantic Web!” (link)

But some of the usage constraints, which seem to be in addition to the W3C’s standard ones, are interesting.

  • “When used on the Web, the logo must be an active link to”, should maintain a high pagerank for the W3C’s Semantic Web project page.
  • “The logo may not be used to disparage W3C, its Member organizations, services, or products.”, sounds eerily like the “no disparaging” clause AT&T had in its its terms and conditions for its ISP customers.

Borjas at UMBC

October 11th, 2007

The well known Labor Economist visited UMBC last week to give a lecture in our humanities series. Borjas is very well known in political circles for his economic analysis of immigration. More importantly, not only does he write scholarly papers, he actually blogs in a way that folks like me who haven’t even done ECON 101 can understand his points. I haven’t read any of his papers to see what they look like, but in his blogs he is fairly clear about his opinions on various issues related to immigration. See for instance this interesting post about “protectionism” on broadway! I don’t always agree with what he has to say, but it is always a pleasure to read well written posts that say something reasonable backed with some data and analytic rigor.

So I went to the lecture with great anticipation. I reached a few minutes late, and the room was already full. The presentation itself was good, but a bit of a letdown. Perhaps because he didn’t want to be too controversial in a “distinguished lecture” type setting ? He presented data (increase in immigration since 1964, concentration of that immigration in select areas making the effect local, confounding factors when you try to analyze wage effects of immigrants, the fact that the wage depressing effects of immigration have most hurt the lower strata of society, the fact that an average immigrant today earns less than the native born, which is a change from the 60s and so on). However, he didn’t go much further by saying something which is both true and a copout — namely that what policy implications you derive from this data will depend on what your objective function is. He joked about letting everyone in if the goal was to alleviate world poverty or somesuch.

I also noticed that he did not split his data into effects of legal and illegal immigration. It would be interesting to know if there are differences ? Amongst legal immigrants, does employment based versus family based immigration make a difference ? Especially when one of the things that the now dead “comprehensive immigration reform” bill was discussing was a points based system for immigration.

Mac Mini to evolve into Mac Nano: smaller, cheaper, faster

October 5th, 2007

Smaller, cheaper, faster. Don’t you wish that automobiles would do this too?

Mac OS Rumors predicts and others concur that Apple will the end of the year will see the Mac Mini replaced by a Mac Nano which is both cheaper and smaller.

“Also, the entry-level model will be dropped to $249 with a 60GB or maybe even 80GB HDD (depending on market conditions about six or seven weeks from now), and two other models at $299 and $399 sporting 120-160 and 200-250GB drives respectively. … the new Mini will be as small in the horizontal as an internal optical drive will allow, and a little over 2/3 the height. Overall volume will be shrunk almost 25%, weight by about 20% and an all-new enclosure will be strikingly different from the design that has been the Mini’s defining feature since its introduction.”

The ebqiuity lab does pervasive computing projects and often need to have a small box to collect data and provide services and control things. This sounds like it will be a good choice for many of these tasks.

It’s a jungle out there

October 4th, 2007


At the end of last week we had a catastrophic failure that resulted in our losing most of our posts. We had a security problem where someone had managed to compromise one of our blog accounts with administrative privileges. Some of the files were modified. We noticed it right away and decided to restore the site files and database from our nightly dump.

However … it turned out that when we did a major WordPress update back in February 2006, we created a new database but failed to update our backup script. So, for the past 19 months, it’s been creating a nightly backup of the old database. Restoring the old database not only resulted in loosing 19 months worth of posts, but also left the database out of sync with the current WordPress version.

One of our former students (thanks Filip!) wrote a script to recover the old posts from Google’s cache and reinsert them into the database. it was a tour de force demonstration of quick programming skill. There are still some problems that we’ll need to attend to — we’ve lost all of the new categories that we’ve added since 2/2006, the ‘related posts’ plugin is no longer working, I think the feed links aren’t all right, etc. But we recovered the posts.

We’ve tightened up our security but continue to see lots of malicious visitors knocking on the door and checking the locks.

It’s a jungle out there.

Search, Google, and Life according to Sergey Brin

October 3rd, 2007

UC Berkeley is posting full lecture videos on YouTube at This includes basic courses on Biology, Chemistry, Literature and Engineering as well as specialized lectures like one by Sergey Brin for SIMS 141 on Search, Google, and Life. If this is part of a new trend, it will definitely help flatten out the academic world. Check out the SIMS 141 schedule for more videos which have not yet been uploaded to Youtube. (link)